# Cosine fun

Geometry Level 3

If $$128\cos^{8}10^{\circ } - 256\cos^{6} 10^{ \circ} + 160 \cos^{4} 10^{\circ } - 32\cos^{2} 10^{\circ } + 1$$ can be expressed in the form $$\cos x^{ \circ}$$ for a positive angle $$x^\circ$$, then what is the value of $$x$$?

×